Shell for artificial joint and method for manufacturing the same

Abstract

To achieve both antibacterial property and control of adhesion to bone.SOLUTION: A shell for an artificial joint comprises: a cup-shaped base having an outer surface that includes a first region and a second region adjacent to the first region; and a coating film including a calcium phosphate material and an antibacterial material, the coating film being arranged so as to straddle the first region and the second region on the outer surface of the base. The surface of the coating film in the first region has greater surface roughness than the surface of the coating film in the second region.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a shell for an artificial joint and a method for manufacturing the same.

Background Art

[0002] The use of biocompatible implants for the treatment of both bone injuries and diseases is constantly expanding with the increase in the active and elderly populations. Among them, coated biocompatible implants are known from the viewpoints of antibacterial properties and bone adhesion.

[0003] For example, Patent Document 1 describes a coating for a medical implant that contains a bone binder in part and an antibacterial metal agent containing silver.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional techniques as described above had room for improvement from the viewpoint of achieving both antibacterial properties and control of bone adhesion.

Means for Solving the Problems

[0006] The shell for an artificial joint according to the present disclosure includes a cup-shaped substrate having an outer surface including a first region and a second region adjacent to the first region, and a coating disposed so as to straddle the first region and the second region of the outer surface of the substrate and including a calcium phosphate-based material and an antibacterial material. The surface of the coating in the first region has a larger surface roughness than the surface of the coating in the second region.

[0007] Furthermore, the method for manufacturing an artificial joint shell according to this disclosure includes the steps of: preparing a cup-shaped base; arranging a first protective material so as to expose a part of the outer surface of the base and protect the other part of the outer surface; a first roughening step of forming a first roughened portion on the portion exposed from the first protective material; a step of removing the first protective material; and a coating forming step of forming a coating containing a calcium phosphate-based material and an antibacterial material on the first roughened portion and at least a part of the other part of the outer surface. [Effects of the Invention]

[0008] According to the invention disclosed herein, it is possible to provide an artificial joint shell that achieves both control over bone adhesion and antibacterial properties. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing an artificial joint shell according to one embodiment, viewed from above. [Figure 2] This is a schematic diagram showing an artificial joint shell according to one embodiment, viewed from a diagonal angle below. [Figure 3] This is a schematic diagram showing a cross-section of an artificial joint shell according to one embodiment, when cut along the line A-A' in Figure 1. [Figure 4] This is a schematic diagram showing an example of a cross-section of the X region in Figure 3, magnified, of an artificial joint shell according to one embodiment. [Figure 5] This is a schematic diagram showing an example of a cross-section of the X region in Figure 3, magnified, of an artificial joint shell according to one embodiment. [Figure 6] This is a schematic diagram showing an example of a cross-section of the X region in Figure 3, magnified, of an artificial joint shell according to one embodiment. [Figure 7] This is a schematic diagram showing an example of a cross-section of the X region in Figure 3, magnified, of an artificial joint shell according to one embodiment. [Figure 8] This is a schematic diagram showing an example of a cross-section of an artificial joint shell according to one embodiment, when cut along line B-B' in Figure 1. [Figure 9]This is a schematic diagram showing an example of a cross-section of the Y region of Figure 8, when the shell for an artificial joint according to one embodiment is magnified. [Figure 10] This is a schematic diagram showing an artificial hip joint according to one embodiment. [Figure 11] This is a schematic diagram showing an example of connecting a device to an artificial hip joint shell according to one embodiment. [Figure 12] This is a schematic diagram showing an example of connecting a device to an artificial hip joint shell according to one embodiment. [Figure 13] This is a process diagram showing a method for manufacturing an artificial joint shell according to one embodiment. [Modes for carrying out the invention]

[0010] One embodiment will be described in detail below. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or greater and B or less".

[0011] [1. Shell for artificial joints] First, the structure of an artificial joint shell 130 according to one embodiment will be described with reference to Figures 1 to 4. Figure 2 is a perspective view of the artificial joint shell 130. As shown in Figure 2, the artificial joint shell 130 has a hemispherical shape, for example, one half of a spherical member, and a coating 20 is arranged on the outer surface of the hemispherical base 10. The coating 20 contains a calcium phosphate-based material and an antibacterial material. The calcium phosphate-based material has the effect of improving adhesion to bone. The antibacterial material has the effect of reducing bacterial adhesion and growth.

[0012] The base body 10 is a member in which the liner 120 described later is arranged. The base body 10 has a cup shape having a concave portion including an opening 12 that opens in one direction. As a result, the liner 120 is arranged in the base body 10 through the opening 12. The base body 10 according to the present embodiment includes a layered member 30 between the outer surface and the coating 20. Further, the base body 10 has screw holes 31 and countersunk holes 32. In the present invention, the base body 10 may not have the layered member 30, the screw holes 31, and the countersunk holes 32.

[0013] As shown in FIG. 2, in the present embodiment, the plane of the artificial joint shell 130 corresponding to the cross section when the sphere is divided so as to include the center of the sphere is taken as the XY plane, and the direction perpendicular to the XY plane and toward the apex of the hemisphere is taken as the Z direction. Further, the Z direction is referred to as the upper side of the artificial joint shell 130.

[0014] FIG. 1 is a schematic view showing a state of the artificial joint shell 130 viewed from above. As shown in FIG. 1, the artificial joint shell 130 has a hemispherical shape as described above. Further, the base body 10 has a hemispherical shape, and the outer surface of the base body 10 has a first surface 301 (lower surface, see FIG. 2) facing downward (negative direction of the Z axis) of the base body 10 and a second surface 302 (outer peripheral surface, see FIG. 2) different from the first surface 301. The first surface 301 is a surface that defines the opening 12, and the second surface 302 is a surface that contacts the pelvis during surgery. In the present embodiment, the first surface 301 is a flat surface, and the second surface 302 is a convex curved surface.

[0015] The cup shape of the base body 10 may be, in addition to the hemispherical shape formed by dividing the aforementioned spherical member into two halves, for example, a spherical segment shape obtained by cutting out a region smaller than half from a sphere, or the other of the two obtained by cutting out a spherical segment shape from a sphere. Further, for example, a semi-elliptical body shape formed by dividing an ellipsoid so as to include the center, an elliptical segment shape obtained by cutting out a region smaller than half from an ellipsoid, or the other of the two obtained by cutting out an elliptical segment shape from an ellipsoid may be used.

[0016] The convex curved surface of the second surface 302 only needs to be convex when the entire second surface 302 is taken as a whole, and there may be a locally concave portion. Also, the convex curved surface of the second surface 302 only needs to be a curved surface when taken as a whole, and there may be a locally flat portion. The inner surface of the concave portion of the base body 10 has a concave curved surface. It only needs to be concave when the entire inner surface is taken as a whole, and there may be a locally convex portion. Also, the concave curved surface of this inner surface only needs to be a curved surface when taken as a whole, and there may be a locally flat portion.

[0017] In addition, the opening 12 when the base body 10 is viewed from the side may be a straight line as shown in FIG. 3, or may be a curve convex upward or a curve convex downward, or may be wavy having portions convex upward and / or portions convex downward two or more times.

[0018] The outer surface of the base body 10 according to the present embodiment includes the first region 1 and the second region 2, and includes the third region 3. Note that the base body 10 according to the present invention may not include the third region 3. Also, the base body 10 according to the present embodiment is provided with the screw hole 31 and the countersink hole 32 described above. In this case, the base body 10 may further include the fourth region 4 and the fifth region 5. Note that in the base body 10 according to the present invention, the fourth region 4 and the fifth region 5 may be absent.

[0019] The first region 1 is a region arranged in at least a part of the region of the outer surface of the base body 10 excluding the end portion of the second surface 302. When the screw hole 31 and the countersink hole 32 are arranged in the base body 10, the first region 1 is a region arranged in at least a part of the region of the outer surface of the base body 10 excluding the end portion of the second surface 302, the periphery of the screw hole 31, and the periphery of the countersink hole 32.

[0020] The second region 2 is adjacent to the first region 1 and is located between the first region 1 and the opening 12 of the base 10. The third region 3 is adjacent to the second region 2 and is located between the second region 2 and the opening 12. The fourth region 4 is adjacent to the first region 1 and is located between the first region 1 and the screw hole 31 or counterbore hole 32. The fifth region 5 is adjacent to the fourth region 4 and is located between the fourth region 4 and the screw hole 31.

[0021] Furthermore, the coating 20 is arranged to span the first region 1 and the second region 2 of the outer surface of the substrate 10, and the surface roughness of the coating in the first region 1 is greater than that of the coating in the second region 2.

[0022] Furthermore, the coating 20 located in the second region 2 may have an end portion 21 and a base portion 22 located on the first region 1 side of the end portion 21, and the thickness of the base portion 22 may be greater than the thickness of the end portion 21.

[0023] Furthermore, when the third region 3 is located on the substrate 10, the outer surface of the substrate 10 located in the third region 3 is exposed from the coating 20. The surface of the coating 20 in the second region 2 has a rougher surface than the outer surface in the third region 3.

[0024] Furthermore, when the fourth region 4 is located on the substrate 10, the outer surface located in the fourth region 4 has a lower surface roughness than the surface of the coating in the first region 1. At least a portion of the outer surface in the fourth region 4 is covered with the coating 20. When the fifth region 5 is located on the substrate 10, the outer surface in the fifth region 5 is entirely exposed from the coating 20.

[0025] Figure 3 shows a cross-section of the artificial joint shell 130 when cut along the line A-A' in Figure 1. Figures 4-7 are schematic diagrams showing an enlarged view of region X in Figure 3.

[0026] The base body 10 has a first region 1 and a second region 2 in that order. If the base body 10 has a third region 3, then, as shown in Figure 4, the first region 1, the second region 2, and the third region 3 are located in that order. It can be understood that the first region 1 and the second region 2, or the first region 1, the second region 2, and the third region 3, are located in that order in a direction parallel to the surface of the base body 10. If the base body 10 does not have a third region, then the second region 2 corresponds to the end of the base body 10 on the side of the opening 12. If the base body 10 has a third region, then the third region 3 corresponds to the end of the base body 10 on the side of the opening 12.

[0027] In Figures 4-7, different hatching is applied to the first region 1, second region 2, and third region 3 for convenience, but these do not need to be different parts. The substrate 10 may consist of a single part. The first region 1, second region 2, and third region 3 can be distinguished in design, for example, by the presence or absence of a coating or the presence or absence of a rough surface as described later. The coating 20 is positioned to straddle the first region 1 and the second region 2. The third region 3 is exposed from the coating 20. Here, if the substrate 10 has a third region 3, the surface roughness of the coating 20 located in the first region 1 is greater than that of the surface of the substrate 10 in the third region 3.

[0028] An example of an index for surface roughness is the arithmetic mean roughness Sa (ISO 25178). The surface roughness (Sa) of the coating 20 located in the first region 1 may be set to, for example, 10 to 80 μm, 20 to 80 μm, or 30 to 70 μm. The surface roughness (Sa) of the substrate 10 in the third region 3 may be set to, for example, less than 1.0 μm.

[0029] The surface roughness Sa of the first region 1 can be determined from the measurement results of the entire first region 1. Similarly, the surface roughness Sa of the second region 2 can be determined from the measurement results of the entire second region 2, and the surface roughness Sa of the third region 3 can be determined from the measurement results of the entire third region 3. For example, within the first region 1, there may be areas where the surface roughness is locally smaller than the surface roughness of the substrate 10 in the second region 2, and within the second region 2, there may be areas where the surface roughness is locally larger than the surface roughness of the coating 20 in the first region 1.

[0030] The surface roughness of the coating 20 or the substrate 10 may be measured, for example, by a stylus or optical method. Furthermore, the surface roughness may be measured, for example, in accordance with "ISO 25178". Note that the measurement of surface roughness is not limited to the methods described above.

[0031] In the past, there has been room for improvement in artificial joint shells from the perspective of achieving both antibacterial properties and control of adhesion to bone. That is, for example, if there are areas with high surface roughness on the surface of the artificial joint shell, the edges of the areas with high surface roughness can irritate bone or soft tissue, potentially becoming the starting point for bacterial infection.

[0032] In the artificial joint shell 130 according to this disclosure, the surface roughness of the coating 20 in the first region 1 is greater than that of the second region 2. Therefore, sufficient adhesion to bone can be ensured. Furthermore, the coating 20 spans both the first region 1 and the second region 2. Thus, the end of the first region can be covered with an antibacterial coating 20, and the artificial joint shell 130 makes it possible to achieve both adhesion to bone and control of antibacterial properties.

[0033] The substrate 10 can be made of metal, ceramics, or plastic. Examples of metals include stainless steel alloys, cobalt-chromium alloys, titanium, and titanium alloys. Examples of titanium alloys include alloys in which at least one of the following is added to titanium: aluminum, tin, zirconium, molybdenum, nickel, palladium, tantalum, niobium, vanadium, and platinum. Examples of ceramics include alumina, zirconia, and alumina-zirconia composite ceramics. Examples of plastics include polyethylene, fluororesins, epoxy resins, polyetheretherketone (PEEK) resin, and bakelite. In this embodiment, the substrate 10 is made of a titanium alloy.

[0034] The first region 1 is covered at least in part by the coating 20. That is, the entire first region 1 may be covered by the coating 20, or only a part of it may be covered by the coating 20. Furthermore, the surface of the coating 20 located in the first region 1 has a rougher surface than the surface of the coating 20 in the second region 2. By providing a region with a rougher surface in this way, the adhesion to bone can be improved. For example, by forming a rough surface in the first region 1 and covering this rough surface with the coating 20, the surface roughness of the coating 20 located in the first region 1 can be increased.

[0035] Furthermore, the surface roughness of the roughened surface formed in the first region 1 is set to be greater than the surface roughness of the second region 2. Therefore, the surface roughness of the coating 20 located in the first region 1 can be made greater than the surface roughness of the coating 20 located in the second region 2. The surface roughness of the roughened surface formed in the first region 1 may be set to, for example, 10 to 80 μm, 20 to 80 μm, or 30 to 70 μm. The surface roughness of the roughened surface can be measured, for example, by cutting the artificial joint shell 130 and observing the cut surface using an SEM or the like. Furthermore, the artificial joint shell 130 according to the present invention is not limited to the case where the surface roughness of the first region 1 is greater than the surface roughness of the second region 2.

[0036] The artificial joint shell 130 may further comprise a layered member 30. The layered member 30 may be placed on the first region 1. As a result, as shown in Figure 4, the first region 1 is higher than the region where the layered member 30 is not provided (for example, the second region 2). Therefore, when the artificial joint shell 130 is implanted in the bone, the first region 1 can be mainly brought into contact with the bone. In this specification, "layered member" means a member different from the coating 20, which is laminated on the base 10. For example, the surface of the layered member 30 may be roughened. This makes it possible to make the region that mainly comes into contact with the bone roughened. The layered member 30 may be formed by thermal spraying as described later. Alternatively, the layered member 30 may be formed as a porous structure. In this embodiment, the surface roughness of the layered member 3 is set to be greater than the surface roughness of the second region 2.

[0037] The height of the layered member 30 may be set to a minimum of 100 μm or more, or to 300 μm or more. The upper limit may be set to a minimum of 1000 μm or less, or to 700 μm or less. The surface roughness of the layered member 30 may be set to a minimum of 10 to 80 μm, or to a minimum of 20 to 80 μm, or to a minimum of 30 to 70 μm.

[0038] Alternatively, the base body 10 may be shaped so that the first region 1 is in contact with the bone, without providing the layered member 30. For example, the first region 1 may be raised relative to the second region 2 and the third region 3.

[0039] The material used for the layered member 30 can be the same material as the material used for the base body 10. For example, the layered member 30 may be made of metal. The material used for the layered member 30 and the material used for the base body 10 may be the same, or they may be different. This ensures sufficient strength. In this embodiment, the layered member 30 is made of the same material as the base body 10. In this embodiment, the layered member 30 is made of a titanium alloy.

[0040] The layered member 30 may have edges that are lower in height compared to the interior of the layered member 30. In this specification, "interior of the layered member" means the inner side of the layered member 30 in the planar direction. Figure 5 shows a layered member 30 having edges that are lower in height compared to the interior. This reduces stress concentration at the edges of the layered member 30.

[0041] The coating 20 includes a calcium phosphate-based material and an antibacterial material. As the calcium phosphate-based material, one or more types selected from the group consisting of hydroxyapatite, α-tricalcium phosphate, β-tricalcium phosphate, tetracalcium phosphate, octacalcium phosphate, and calcium phosphate-based glass can be used. As the antibacterial material, natural antibacterial agents, organic antibacterial agents, and inorganic antibacterial agents can be used. For example, hinokitiol can be used as a natural antibacterial agent, benzalkonium chloride as an organic antibacterial agent, and metals can be used as inorganic antibacterial agents, such as silver, copper, and zinc. In addition to the calcium phosphate-based material and the antibacterial material, the coating 20 may also contain glass ceramics and antibacterial agents such as penicillin and vancomycin.

[0042] The concentration of the antibacterial material in the coating 20 may be, for example, 0.05% to 3.00% by weight, 0.05% to 2.50% by weight, 0.05% to 1.00% by weight, or 0.1% to 1.00% by weight. A concentration of 0.05% by weight or higher of the antibacterial material provides sufficient antibacterial properties. Furthermore, a concentration of 3.00% by weight or lower reduces the burden on biological tissue.

[0043] The coating 20 may be arranged on the layered member 30. As described above, the layered member 30 can mainly come into contact with bone. The presence of the coating 20 on the layered member 30 can further improve adhesion to bone and antibacterial properties.

[0044] The height of the layered member 30 may be greater than the thickness of the coating 20. This makes the area where the layered member 30 is formed higher than the area where only the coating 20 is formed, so that the area where the layered member 30 is formed can be mainly brought into contact with the bone. The thickness of the coating 20 may be set to less than 100 μm, for example, or less than 50 μm. Alternatively, the thickness of the coating 20 may be set to 5 μm or more, for example.

[0045] The second region 2 is covered at least in part by the coating 20. That is, the second region 2 may be entirely covered by the coating 20, or only partially covered by the coating 20. In this specification, when the coating 20 "spans the first and second regions", it means that at least a portion of the boundary between the first region 1 and the second region 2 is covered by the coating 20. That is, the boundary between the first region 1 and the second region 2 may be entirely covered by the coating 20, or only partially covered by the coating 20. When the layered member 30 is placed in the first region 1, the coating 20 may extend from the first region 1 to the second region 2 so as to cover the edges of the layered member 30. That is, the edges of the layered member 30 can be prevented from being exposed from the coating 20. This can further reduce bacterial growth.

[0046] The coating 20 located in the second region 2 may have an end portion 21 and a base portion 22 located closer to the first region 1 than the end portion 21. In this specification, "end portion of the coating located in the second region" means the region of the coating 20 located in the second region 2 that is closer to the boundary between the second region 2 and the third region 3. Also, "base portion of the coating located in the second region" means the region of the coating 20 located in the second region 2 that is closer to the boundary between the first region 1 and the second region 2. Here, the thickness of the base portion 22 may be greater than the thickness of the end portion 21. Figure 6 shows a coating 20 in which the thickness of the base portion 22 is greater than the thickness of the end portion 21. This reduces the concentration of stress near the boundary between the first region 1 and the second region 2, and as a result, peeling of the coating 20 can be reduced. If a layered member 30 is arranged in the first region 1, the concentration of stress near the edge of the layered member 30 can be reduced.

[0047] The third region 3 is exposed from the coating 20. Distinguishing between the area covered by the coating 20 and the area exposed from the coating 20 is possible by elemental analysis of the surface of each region. Elemental analysis can be performed, for example, by mapping surface elements using an energy-dispersive X-ray spectrometer (EDX), which is an accessory to a general scanning electron microscope (SEM). Alternatively, surface analysis methods such as X-ray photoelectron spectroscopy, Auger electron spectroscopy, and secondary ion mass spectrometry may be used. Furthermore, elements may be confirmed by chemical analysis of samples obtained by mechanically scraping the surface of each region. For example, phosphorus, calcium, antibacterial components, etc., are detected on the surface of at least a portion of the first region 1 and at least a portion of the second region 2 where the coating 20 is placed. On the surface of the third region 3, elements constituting the substrate 10 are detected, while phosphorus, calcium, antibacterial components, etc., are not detected or are below the noise level.

[0048] The surface roughness of the coating 20 located in the second region 2 may be less than that of the coating 20 located in the first region 1. Figure 7 shows an embodiment in which the surface roughness of the coating 20 located in the second region 2 is less than that of the coating 20 located in the first region 1. This ensures sufficient adhesion to bone and antibacterial properties in the first region 1. In addition, physical irritation to soft tissue can be reduced in the second region 2.

[0049] The surface roughness (Sa) of the coating 20 located in the first region 1 may be set to, for example, 10 to 80 μm, 20 to 80 μm, or 30 to 70 μm. The surface roughness (Sa) of the coating 20 located in the second region 2 may be set to, for example, 0.1 to 10 μm.

[0050] Furthermore, the surface roughness of the coating 20 located in the second region 2 may be greater than that of the outer surface of the substrate 10 in the third region 3. Figure 7 also shows an embodiment in which the surface roughness of the coating 20 located in the second region 2 is greater than that of the substrate 10 in the third region 3. As a result, the adhesion between the coating 20 and the substrate 10 is improved in the second region 2, so that sufficient adhesion to bone and antibacterial properties can be ensured. In addition, physical irritation to soft tissue can be reduced in the third region 3. Note that the surface roughness (Sa) of the substrate 10 in the third region 3 may be set to, for example, less than 1 μm.

[0051] Furthermore, as shown in Figure 7, the surface roughness of the outer surface of the substrate 10 in the second region 2 may be greater than the surface roughness of the outer surface of the substrate 10 in the third region 3. This improves the adhesion between the coating 20 and the substrate 10 in the second region 2, and reduces peeling of the coating 20. The surface roughness (Sa) of the substrate 10 in the second region 2 should be set to 0.1 μm or more and less than 10 μm, and may also be set to less than 2.0 μm.

[0052] Furthermore, in this embodiment, the surface roughness of the substrate 10 in the first region 1 (including the rough surface of the layered member 30) is set to be greater than the surface roughness of the substrate 10 in the third region 3.

[0053] Figure 8 shows a cross-section of the artificial joint shell 130 when cut along the line B-B' in Figure 1. Figure 9 is a schematic diagram showing an enlarged view of region Y in Figure 8. As shown in Figure 9, the width of the through-hole 321 (second through-hole) on the outer surface side of the counterbore 32 is smaller than the width of the through-hole 322 (first through-hole) on the opening 12 side. That is, the counterbore 32 has a through-hole 322 and a through-hole 321 that is connected to the through-hole 322 and the outer surface and is narrower than the through-hole 322.

[0054] In other words, the base body 10 may have at least one through hole (screw hole 31, counterbore hole 32) that penetrates the outer surface and the inner surface of the base body 10 (the side facing the opening 12). Of the through holes, at least one (screw hole 31) is positioned further away from the opening 12 compared to the other position (counterbore hole 32). The other through hole, the counterbore hole 32, can be said to have a through portion 322 and a through portion 321 that connects to the through portion 322 and the outer surface and is narrower than the through portion 322.

[0055] The artificial joint shell 130 may also have a configuration having one or more fins.

[0056] [Screw hole 31 and countersunk hole 32] The screw hole 31 is used, for example, to connect an instrument to the artificial joint shell 130 during surgery. For example, as shown in Figure 11, by fixing the tip of the holder 310 to the screw hole 31 of the artificial joint shell 130, the holder 310 can hold the artificial joint shell 130 and move the artificial joint shell 130 to a desired position.

[0057] The counterbore 32 can be used, for example, to fix the artificial joint shell 130 to the hip bone 93 with a screw 320, as shown in Figure 12.

[0058] With the above configuration, the artificial joint shell 130 according to this disclosure can further improve bone conduction and bone fixation by having a rough surface. Furthermore, since the coating covers the ends of the rough surface so that they are not exposed, it is possible to prevent bacteria from growing from the ends of the rough surface.

[0059] Furthermore, the smooth surface of the cup-shaped rim, which is prone to stress, reduces physical irritation to soft tissue. Additionally, the slightly lowered edge of the shell further reduces irritation at the edges.

[0060] Furthermore, the fact that the layered members are made of metal ensures sufficient strength, and the presence of a coating on the layered members enhances adhesion to bone and antibacterial properties.

[0061] Furthermore, because the height of the metal layer's edges is lower than that of the interior, stress concentration at the edges of the roughened surface can be prevented.

[0062] Furthermore, it can prevent the overcoat from peeling off at the edges.

[0063] Furthermore, while ensuring sufficient adhesion to bone and antibacterial properties in the second region 2, the surface roughness of the third region 3 is small, which further reduces irritation to soft tissue.

[0064] Furthermore, by applying the coating to the outer surface of the substrate 10 in the second region, which has a greater surface roughness than the outer surface of the substrate 10 in the third region 3, the adhesion between the coating and the substrate is improved, and the coating becomes less likely to peel off the substrate.

[0065] Furthermore, it can be fixed to the jig or acetabulum at a desired position.

[0066] If the base body 10 has screw holes 31 and counterbore holes 32, then the base body 10 has the first region 1, the fourth region 4, and the screw holes 31 or counterbore holes 32 in that order. If the base body 10 has a fifth region 5, then the base body 10 has the first region 1, the fourth region 4, the fifth region 5, and the screw holes 31 in that order. It can be understood that the first region 1, the fourth region 4, the screw hole 31 or counterbore hole 32, or the first region 1, the fourth region 4, the fifth region 5, and the screw hole 31 are located sequentially in a direction parallel to the surface of the base body 10. Therefore, if the base body 10 does not have the fifth region 5, the fourth region 4 corresponds to the end of the base body 10 on the side of the screw hole 31 and the counterbore hole 32. Also, if the base body 10 has the fifth region 5, the fifth region 5 corresponds to the end of the base body 10 on the side of the screw hole 31, and the fourth region 4 corresponds to the end of the base body 10 on the side of the counterbore hole 32. The fourth region may be entirely covered by the coating 20, or only partially covered. The boundary between the first and fourth regions does not have to be covered by the coating 20, but it may be entirely covered by the coating 20, or only partially covered. When the boundary between the first and fourth regions 4 is covered by the coating 20, and a layered member 30 is placed in the first region 1, the coating 20 can extend from the first region 1 to the fourth region 4 so as to cover the edges of the layered member 30. In other words, the edges of the layered member 30 can be prevented from being exposed from the coating 20. This can further reduce bacterial growth.

[0067] Region 5 is exposed from the coating 20. Distinguishing between the areas covered by the coating 20 and those exposed from the coating 20 is possible by elemental analysis of the surface of each region. Elemental analysis can be performed, for example, by mapping surface elements using an energy-dispersive X-ray spectrometer (EDX), which is an accessory to a general scanning electron microscope (SEM). Alternatively, surface analysis methods such as X-ray photoelectron spectroscopy, Auger electron spectroscopy, and secondary ion mass spectrometry may be used. Furthermore, elements may be confirmed by chemical analysis of samples obtained by mechanically scraping the surface of each region. For example, phosphorus, calcium, antibacterial components, etc., are detected on the surface of at least a portion of Region 1 where the coating 20 is placed and at least a portion of Region 4. On the surface of Region 5, elements constituting the substrate 10 are detected, while phosphorus, calcium, antibacterial components, etc., are not detected or are below the noise level.

[0068] The surface of the coating 20 located in the fourth region 4 may have a lower surface roughness than the surface of the coating 20 located in the first region 1. This reduces physical irritation to the soft tissue in the fourth region 4.

[0069] Furthermore, the surface roughness (Sa) of the coating 20 located in the fourth region 4 should be set to, for example, 0.1 to 10 μm.

[0070] Furthermore, the surface roughness of the coating 20 located in the fourth region 4 may be greater than that of the outer surface of the substrate 10 in the fifth region 5. The surface roughness (Sa) of the substrate 10 in the fifth region 5 may be set to, for example, less than 1 μm.

[0071] Furthermore, the surface roughness of the outer surface of the substrate 10 in the fourth region 4 may be greater than the surface roughness of the outer surface of the substrate 10 in the third region 3 or the fifth region 5. This improves the adhesion between the coating 20 and the substrate 10 in the fourth region 4 and reduces peeling of the coating 20. The surface roughness (Sa) of the substrate 10 in the fourth region 4 should be set to 0.1 μm or more and less than 10 μm, and may also be set to less than 2.0 μm.

[0072] [2. Method for manufacturing shells for artificial joints] A method for manufacturing an artificial joint shell according to one embodiment includes the steps of: preparing a cup-shaped base; arranging a first protective material so as to expose a part of the outer surface of the base and protect the other part of the outer surface (S101); a first roughening step (S102) to form a first roughened portion on the portion exposed from the first protective material; a step (S103) to remove the first protective material; and a coating forming step (S108) to form a coating 20 containing a calcium phosphate-based material and an antibacterial material on the first roughened portion and at least a part of the other part of the outer surface.

[0073] This makes it possible to obtain an artificial joint shell in which the coating 20 is positioned to straddle the first region 1 and the second region 2, and the surface of the coating 20 located in the first region 1 has a greater surface roughness than the surface of the substrate 10 in the second region 2.

[0074] The cup-shaped base can be formed by molding processes such as casting, plastic deformation, or sintering, for example, when using metal as the material. After being formed by the molding process, the shape may be further refined by removal processes such as cutting, grinding, or electrical discharge machining. The screw holes 31 or counterbore holes 32 may be formed during the molding process, or they may not be formed during the molding process but may be formed during the removal process.

[0075] In the first surface roughening step, a rough surface can be formed by at least one of the following methods: thermal spraying, additive manufacturing, chemical etching, and blasting. Compared to blasting, thermal spraying, additive manufacturing, or chemical etching can achieve a greater surface roughness. As the thermal spraying material and additive manufacturing material, the materials exemplified as the material for the substrate 10 can be used. The layered structure described above may be formed by thermal spraying or additive manufacturing. Examples of chemical etching methods include alkali treatment. Examples of blasting methods include sandblasting. Note that the rough surface can be formed before forming the coating 20.

[0076] The coating 20 can be formed by thermal spraying methods such as flame spraying, high-velocity flame spraying, and plasma spraying. It can also be formed by physical or chemical vapor deposition methods such as sputtering, ion plating, ion beam deposition, and ion mixing. Furthermore, it can be formed by wet coating methods such as the sol-gel method.

[0077] Protective materials may be used to form a rough surface or coating 20 only in the desired area. For example, masking tape or a screen may be used as the protective material. Alternatively, a jig that covers the substrate 10 may be used as the protective material. Examples of materials for these protective materials include metals, glass, resins, and composite materials thereof.

[0078] The protective material may or may not be in contact with the base 10. If the protective material is not in contact with the base 10, the thermal spray material or coating material may wrap around from the edge of the protective material and adhere to the area covered by the protective material to some extent. As a result, a layered member 30 having an edge that is lower in height compared to the interior, and / or a coating 20 in which the thickness of the base 22 is greater than the thickness of the end 21 may be formed, as described above. As the protective material, for example, a masking tape that is adhesive and can be attached to the base 10, or a jig that covers the base 10 as described later can be used.

[0079] When a screen is used, the position of the screen can be moved each time a rough surface or coating 20 is formed to form a rough surface or coating 20 in a specific area. When a jig is used, the area covered by the jig can be changed each time a rough surface or coating 20 is formed to form a rough surface or coating 20 in a specific area. In this case, for example, by adjusting the positional relationship between the discharge nozzle that discharges the thermal spray material or coating material and the screen, it is also possible to selectively form a rough surface or coating 20 only in a desired area. In this case, the tip of the discharge nozzle should be positioned in a straight line with the surface of the desired area without being separated by a screen. The coating material refers to the material that constitutes the coating. In the first roughening step, the surface of the first area 1 and the tip of the discharge nozzle should be positioned in a straight line without being separated by a screen. In the coating formation step, the discharge nozzle should be positioned in a straight line with the surface of the area spanning the first area 1 and the second area 2, without being separated by a screen. If the base body 10 is provided with screw holes 31 and / or counterbore holes 32, the surface of the first region 1, the region spanning the second region 2, and the fourth region 4, and the tip of the discharge nozzle may be arranged in a straight line without a partition separating them. Also, when forming a coating 20 on the first region 1 and the second region 2 simultaneously, considering the diffusion of the material, the tip of the discharge nozzle may be arranged in a straight line with, for example, the surface of the first region 1 without a partition separating it. The method is not limited to these, and the rough surface or coating 20 may be formed with the base body 10, the partition, and the discharge nozzle fixed, or the rough surface or coating 20 may be formed while at least one of them is moved. Furthermore, the angle of the discharge nozzle may be fixed, or it may be changed while forming the rough surface or coating 20.

[0080] Furthermore, it is possible to form a rough surface or coating 20 only in the desired area without using a protective material. For example, by adjusting the shape, angle, or position of the discharge nozzle that discharges the thermal spray material or coating material, it is possible to selectively form a rough surface or coating 20 only in the desired area. For example, the thermal spray material or coating material may be discharged with the discharge nozzle positioned above the surface of the desired area. In the first roughening step, the thermal spray material may be discharged with the discharge nozzle positioned above the surface of the first area 1. In the coating formation step, the coating material may be discharged with the discharge nozzle positioned above the surface of the area spanning the first area 1 and the second area 2. If the base body 10 is provided with screw holes 31 and / or counterbore holes 32, the coating material may be discharged with the discharge nozzle positioned above the surface of the area spanning the first area 1 and the second area 2, and the surface of the fourth area 4. In this case, the base 10 may be fixed and the rough surface or coating 20 may be formed while moving the position and angle of the discharge nozzle, or the discharge nozzle may be fixed and the rough surface or coating 20 may be formed while moving the position and angle of the base 10. The discharge nozzle may be moved at a constant speed or at a variable speed. In addition, the discharge direction of the thermal spray material or coating material may form an angle of 90° or less than 90° with a vector extended from the tip of the discharge nozzle toward the surface of the base 10 or rough surface that is the shortest distance from the tip of the discharge nozzle.

[0081] For example, in the first roughening step, the first protective material may be placed on the substrate 10 so as to expose the first region 1 while protecting the second region 2, and a rough surface may be formed on the exposed first region 1. If the substrate 10 is provided with screw holes 31 and / or counterbore holes 32, the first protective material may be placed so as to expose the first region 1 while protecting the second region 2, the fourth region 4 and the fifth region 5, and a rough surface may be formed on the exposed first region 1.

[0082] Furthermore, the manufacturing method according to this disclosure may further include a step of removing the first protective material after the first roughening step and before the coating formation step.

[0083] Furthermore, after removing the first protective material, a process may be performed to shave the edges of the rough surface, for example, the edges of the layered member 30. This avoids stress concentration at the edges of the layered member 30 and reduces irritation to biological tissue.

[0084] A first masking tape may be used as the first protective material. In this case, the manufacturing method according to the present disclosure may further include a step of applying the first masking tape to the second region 2 while exposing the first region 1, before the first roughening step. Furthermore, if the base body 10 is provided with screw holes 31 and / or counterbore holes 32, the method may further include a step of applying the first masking tape to the second region 2, the fourth region 4 and the fifth region 5 while exposing the first region 1.

[0085] Furthermore, the manufacturing method according to this disclosure may further include, after the step of removing the first protective material and before the film forming step, a step of arranging a second protective material so as to expose a part of the other part of the outer surface and protect the other part of the outer surface (S104), and a second roughening step of forming a second roughened portion on at least a part of the other part of the outer surface (S105), wherein the second roughened portion may be formed on the part exposed from the second protective material. Furthermore, the method may also include a step of removing the second protective material (S106) after the second roughening step.

[0086] In the second roughening step, the rough surface may be formed by at least one of chemical etching and / or blasting. The second roughening step may be carried out such that the surface roughness of the second roughened portion formed in the second roughening step is less than that of the first roughened portion in the first region 1. When forming the second roughened portion, the rough surface in the first region 1 may also be referred to as the first roughened portion.

[0087] A second masking tape may be used as the second protective material. In this case, the manufacturing method according to the present disclosure may further include a step of applying the second masking tape to the third region 3 while exposing the first region 1 and the second region 2, before the second roughening step. Furthermore, if the base body 10 is provided with screw holes 31 and / or counterbore holes 32, the method may further include a step of applying masking tape to the third region 3 and the fifth region 5 while exposing the first region 1 and the fourth region 4.

[0088] The manufacturing method according to this disclosure may further include a step (S107) after the step of removing the second protective material and before the film formation step of arranging the third protective material so as to expose the first rough surface and a part of the second rough surface and protect the other part of the second rough surface and the outer surface. This allows the film to be formed on the first rough surface and a part of the second rough surface exposed from the third protective material during the film formation step. If the base body 10 is provided with screw holes 31 and / or counterbore holes 32, the step (S107) may further include a step (S107) of arranging the third protective material so as to expose a part of the second rough surface and a fourth region 4 and protect the other part of the second rough surface, a fifth region 5, and the outer surface. This allows the film to be formed on the first rough surface, a part of the second rough surface, and a fourth region 4 exposed from the third protective material during the film formation step.

[0089] A third masking tape may be used as the third protective material. In this case, the manufacturing method according to the present disclosure may further include a step of applying the third masking tape to the other part of the second region 2 while exposing the first region 1 and a part of the second region 2, before the film formation step. If the base body 10 is provided with screw holes 31 and / or counterbore holes 32, the method may further include a step of applying masking tape to the other part of the second region 2 and the fifth region 5 while exposing the first region 1, a part of the second region 2 and the fourth region.

[0090] Furthermore, the manufacturing method relating to this disclosure may include a hole-forming step in which holes are formed in the substrate during the step of preparing the substrate.

[0091] In the second roughening step, the first region 1 may or may not be covered by a protective material. The first region 1 may be protected, and at least one of chemical etching and blasting may be performed only on the second region 2. If the substrate 10 is provided with screw holes 31 and / or counterbore holes 32, at least one of chemical etching and blasting may be performed on the second region 2 and the fourth region. Alternatively, the second protective material may be placed so as to expose the first region 1, and at least one of chemical etching and blasting may be performed on the roughened surface of the exposed first region 1 and the second region 2. If the substrate 10 is provided with screw holes 31 and / or counterbore holes 32, at least one of chemical etching and blasting may be performed on the roughened surface of the first region 1, the second region 2 and the fourth region. This allows for the removal of excess thermal spray material remaining on the rough surface of the first region 1, and the formation of a rough surface in the second region 2. If the base body 10 is provided with screw holes 31 and / or counterbore holes 32, rough surfaces can also be formed in the second region 2 and the fourth region.

[0092] Furthermore, it is also possible to form a second roughened surface only in a desired area without using a protective material. For example, by adjusting the shape, angle, or position of the discharge nozzle that discharges the chemical etching material or blasting material, it is possible to selectively form a second roughened surface only in a desired area. Note that chemical etching material refers to the material discharged toward the substrate 10 when processing by a chemical etching method. Similarly, blasting material refers to the material discharged toward the substrate 10 when processing by a blasting method. For example, the chemical etching material or blasting material may be discharged with the discharge nozzle positioned above the surface of the desired area. When forming a second roughened surface only in the second area 2, the chemical etching material or blasting material may be discharged with the discharge nozzle positioned above the surface of the second area 2. When forming a second roughened surface in both the first area 1 and the second area 2, the chemical etching material or blasting material may be discharged with the discharge nozzle positioned above the surfaces of both the first area 1 and the second area 2. The base body 10 is provided with screw holes 31 and / or counterbore holes 32, and when forming a second roughened surface in the first region 1, the second region 2, and the fourth region 4, the discharge nozzle may be positioned above the surfaces of the first region 1, the second region 2, and the fourth region 4 when discharging the chemical etching material or blasting material. In this case, the base body 10 may be fixed and the second roughened surface may be formed while moving the position and angle of the discharge nozzle, or the discharge nozzle may be fixed and the second roughened surface may be formed while moving the position and angle of the base body 10. The discharge nozzle may be moved at a constant speed or at a variable speed. Furthermore, the discharge direction of the chemical etching material or blasting material may form an angle of 90° or less than 90° with a vector extended from the tip of the discharge nozzle towards the surface of the base body 10 or the roughened surface at the shortest distance from the tip of the discharge nozzle.

[0093] For example, thermal spraying may be used in the first surface roughening step and the coating formation step, and blasting may be used in the second surface roughening step. In this case, a material with higher heat resistance than the second protective material can be used as the first protective material. Furthermore, a material with higher heat resistance than the third protective material can be used as the first protective material. Furthermore, a material with higher heat resistance than the second protective material can be used as the third protective material. To satisfy such relationships, for example, a material that does not melt or decompose for 1 minute under thermal spraying conditions of 8000°C may be used as the first protective material, a material that does not melt or decompose for 1 minute under thermal spraying conditions of 3000°C may be used as the third protective material, and a material that does not melt or decompose at room temperature may be used as the second protective material. Specifically, such materials may be a composite material of glass and resin as the first protective material, a composite material of glass and resin as the third protective material, and resin as the second protective material.

[0094] When a jig is used to cover the base 10 as a protective material, the shape of the jig is not particularly limited, but it may be cylindrical, for example. The cross-section of the cylindrical jig may be polygonal or circular.

[0095] To summarize the above, each step can be performed in the order shown in Figure 13, for example. Figure 13 is a process diagram showing a method for manufacturing an artificial joint shell according to one embodiment. First, a first protective material is placed, then a roughening step 1 is performed, and then the first protective material can be removed. Next, a second protective material is placed, then a roughening step 2 is performed, and then the second protective material can be removed. Finally, a third protective material is placed, and then a coating formation step can be performed.

[0096] Furthermore, the manufacturing method according to this disclosure may or may not include a cleaning step between each step. For example, the manufacturing method according to this disclosure may include a step of cleaning the substrate 10, or the substrate 10 and the layered member 30 disposed on the first region 1, after the first roughening step. It may also further include a step of cleaning the substrate 10, or the substrate 10 and the layered member 30 disposed on the first region 1, after the second roughening step. The cleaning method is not particularly limited, but may be, for example, immersion in a liquid such as water or an organic solvent such as alcohol, or showering using the liquid. Alternatively, it may be a method of blowing a gas such as air, nitrogen, or argon. This makes it possible to remove excess thermal spray material etc. generated by the first roughening step and / or shavings etc. generated by the second roughening step.

[0097] [3. Use of shells for artificial joints] The artificial joint shell 130 shown in Figure 1 is primarily shaped for use as an artificial hip joint shell, but the artificial joint to which the artificial joint shell according to this disclosure is applied is not limited to the artificial hip joint. Examples of artificial joints include artificial hip joints, artificial shoulder joints, and artificial elbow joints.

[0098] An example of using an artificial joint shell 130 as part of an artificial hip joint 1000 is described below with reference to Figure 10. In addition to the artificial joint shell 130, the artificial hip joint 1000 may include an artificial joint stem 100, a femoral head 110, and a liner 120. The artificial joint stem 100 and the femoral head 110 may be made of the same material as the base 10 of the artificial joint shell 130, or they may be made of different materials. The artificial joint stem 100 is implanted in the femur 91. The femoral head 110 is positioned on the exposed portion of the artificial joint stem 100. The artificial joint shell 130 is fixed to the acetabulum 94 of the pelvic bone 93, and functions as a hip joint by fitting the femoral head 110 into the recess of the artificial joint shell 130 and allowing it to slide. More precisely, the hip joint functions by fitting the femoral head 110 into a recess in the liner 120, which is fitted into the opening 12 of the artificial joint shell 130, and allowing it to slide.

[0099] The inventions described in this disclosure have been explained above based on the drawings and embodiments. However, the inventions described in this disclosure are not limited to the embodiments described above. That is, the inventions described in this disclosure can be modified in various ways within the scope shown in this disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the inventions described in this disclosure. In other words, it should be noted that it is easy for those skilled in the art to make various modifications or alterations based on this disclosure. Furthermore, it should be noted that these modifications or alterations are included in the scope of this disclosure. [Explanation of symbols]

[0100] 1 1st area 2 Second area 3 Third area 4 4th area 5 5th area 10 Base 20 Coating 21 Edge of the coating 22 Base of the coating 30-layer member 100 Artificial joint stems 110 femoral head 120 Liner 130 Artificial joint shell 1000 artificial hip joints

Claims

1. A cup-shaped base having an outer surface including a first region and a second region adjacent to the first region, The substrate comprises a coating comprising a calcium phosphate-based material and an antibacterial material, which is arranged to span the first and second regions of the outer surface of the substrate, The surface of the coating in the first region has a greater surface roughness than the surface of the coating in the second region. The second region is located between the first region and the opening of the substrate. The outer surface of the substrate further has a third region adjacent to the second region and located between the second region and the opening. The outer surface of the substrate located in the third region is exposed from the coating, An artificial joint shell wherein the surface of the coating in the second region has a greater surface roughness than the outer surface in the third region.

2. The shell for an artificial joint according to claim 1, wherein the substrate further comprises a layered member disposed in the first region.

3. The shell for an artificial joint according to claim 2, wherein the layered member is made of metal.

4. The shell for an artificial joint according to claim 2 or 3, wherein the coating disposed in the first region is disposed on the layered member.

5. The shell for an artificial joint according to any one of claims 2 to 4, wherein the thickness of the layered member on the third region side is thinner than the others.

6. The coating located in the second region has an end portion and a base portion located on the first region side of the end portion. The shell for an artificial joint according to any one of claims 1 to 5, wherein the thickness of the base is greater than the thickness of the end.

7. The shell for an artificial joint according to any one of claims 1 to 6, wherein the outer surface in the first region has a greater surface roughness than the outer surface in the second region.

8. The shell for an artificial joint according to any one of claims 1 to 7, wherein the outer surface in the second region has a greater surface roughness than the outer surface in the third region.

9. The shell for an artificial joint according to any one of claims 1 to 8, wherein the substrate has at least one through hole that penetrates the outer surface of the substrate and the inner surface of the substrate.

10. A cup-shaped base having an outer surface including a first region and a second region adjacent to the first region, The substrate comprises a coating comprising a calcium phosphate-based material and an antibacterial material, which is arranged to span the first and second regions of the outer surface of the substrate, The surface of the coating in the first region has a greater surface roughness than the surface of the coating in the second region. The second region is located between the first region and the opening of the substrate. The substrate has at least one through hole that penetrates the outer surface and the inner surface of the substrate, The outer surface of the substrate further has a fourth region adjacent to the first region and located between the first region and the through hole. The outer surface located in the fourth region has a surface roughness less than that of the coating surface in the first region, in the shell for an artificial joint.

11. Of the aforementioned through holes, at least one is located at a position further away from the opening than the other positions, and is a screw hole. The shell for an artificial joint according to claim 10, wherein at least one of the other through holes is a counterbore having a first through portion and a second through portion connected to the first through portion and the outer surface, and narrower than the first through portion.

12. The shell for an artificial joint according to claim 11, wherein the outer surface in the fourth region is coated with the coating on at least a portion of it.

13. The outer surface of the substrate further has a fifth region adjacent to the fourth region and located between the fourth region and the screw hole. The shell for an artificial joint according to claim 12, wherein the outer surface in the fifth region is entirely exposed from the coating.

14. The fourth region is adjacent to the counterbore hole, as described in claim 11, for the artificial joint shell.

15. The process of preparing a cup-shaped base, A step of arranging a first protective material so as to expose a part of the outer surface of the substrate and protect the other part of the outer surface, A first roughening step is performed to form a first roughened surface on the portion exposed from the first protective material, The process of removing the first protective material, The process includes a coating-forming step of forming a coating containing a calcium phosphate-based material and an antibacterial material on the first roughened surface and a portion of the other parts of the outer surface, After the step of removing the first protective material, and before the film formation step, The process further includes a second roughening step of forming a second roughened portion on at least a part of the other portion of the outer surface, In the coating formation step, the coating is formed on the first roughened portion and a part of the second roughened portion. A method for manufacturing an artificial joint shell, wherein the surface of the coating in the second roughened portion has less surface roughness than the surface of the coating in the first roughened portion, and has greater surface roughness than the other parts of the outer surface where the second roughened portion is not formed.

16. After the step of removing the first protective material, and before the second surface roughening step, The process further includes the step of arranging a second protective material such that a portion of the other portion of the outer surface is exposed and the other portion of the outer surface is protected. The method for manufacturing an artificial joint shell according to claim 15, wherein in the second roughening step, a second roughened portion is formed on the portion exposed from the second protective material.

17. After the second surface roughening step and before the coating formation step, The process includes removing the second protective material, A method for manufacturing an artificial joint shell according to claim 16.

18. After the step of removing the second protective material, and before the film formation step, The process further includes the step of arranging a third protective material so as to expose the first roughened portion and a portion of the second roughened portion, and to protect the other portion of the second roughened portion and the outer surface, The method for manufacturing an artificial joint shell according to claim 17, wherein in the coating formation step, the coating is formed on the first roughened portion and a part of the second roughened portion that are exposed from the third protective material.

19. In the step of arranging the second protective material, the second protective material is arranged such that the first roughened portion is exposed. A method for manufacturing an artificial joint shell according to any one of claims 16 to 18, wherein in the second surface roughening step, the first roughened portion exposed from the second protective material is processed by a blasting method.

20. A method for manufacturing an artificial joint shell according to any one of claims 16 to 19, wherein the first protective material has higher heat resistance than the second protective material.

21. After the step of removing the second protective material, and before the film formation step, The process includes a step of arranging a third protective material so as to expose a part of the first roughened surface and a part of the second roughened surface, and to protect the other part of the second roughened surface and the outer surface, A method for manufacturing an artificial joint shell according to any one of claims 18 to 20, wherein the first protective material has higher heat resistance than the third protective material.

22. After the step of removing the second protective material, and before the film formation step, The process includes a step of arranging a third protective material so as to expose a part of the first roughened surface and a part of the second roughened surface, and to protect the other part of the second roughened surface and the outer surface, A method for manufacturing an artificial joint shell according to any one of claims 18 to 21, wherein the third protective material has higher heat resistance than the second protective material.

23. As the first protective material, the first masking tape is used. A method for manufacturing an artificial joint shell according to any one of claims 16 to 22, further comprising the step of applying the first masking tape to other parts of the outer surface such that a part of the outer surface is exposed in the step of arranging the first protective material.

24. As the second protective material, a second masking tape is used. A method for manufacturing an artificial joint shell according to any one of claims 16 to 23, further comprising the step of applying the second masking tape to the other part of the outer surface such that the other part of the outer surface is exposed in the step of arranging the second protective material.

25. After the step of removing the second protective material, and before the film formation step, The process includes a step of arranging a third protective material so as to expose a part of the first roughened surface and a part of the second roughened surface, and to protect the other part of the second roughened surface and the outer surface, As the third protective material, a third masking tape is used. A method for manufacturing an artificial joint shell according to any one of claims 18 to 24, further comprising the step of applying the third masking tape to the other portion of the second roughened surface and the outer surface such that a portion of the second roughened surface is exposed in the step of arranging the third protective material.

26. A method for manufacturing an artificial joint shell according to any one of claims 16 to 25, comprising a hole-forming step of forming a hole in the substrate in the step of preparing the substrate.

27. After the step of removing the first protective material and before the film formation step, a step of arranging a second protective material so as to expose a part of the other part of the outer surface and protect the other part of the outer surface, The process includes a second roughening step of forming a second roughened portion on the portion exposed from the second protective material, and a step of arranging a third protective material so as to expose the first roughened portion and a portion of the second roughened portion, and to protect the other portion of the second roughened portion and the outer surface. In the first roughening step, the edge of the hole is protected with the first protective material, and in the second roughening step, the edge of the hole is exposed from the second protective material. The method for manufacturing an artificial joint shell according to claim 26, wherein in the coating formation step, the edge of the hole is exposed from the third protective material.

28. The method for manufacturing an artificial joint shell according to any one of claims 15 to 27, wherein the first surface roughening step is performed by at least one of a thermal spraying method and a blasting method.

29. The method for manufacturing an artificial joint shell according to any one of claims 15 to 28, wherein the second surface roughening step is performed by a blasting method.

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